The present invention relates to electronic instrumentation, and more particularly, to improvements in devices used to control the spacing between adjacent elements in such instrumentation.
The precise positioning of component parts, such as planar elements in the form of printed circuit boards, of an electronic instrument can be requisite to the correct functioning of that instrument. Proper alignment of adjacent printed circuit boards, or the like, has been accomplished in the prior art by devices such as stand-offs.
In one form, such stand-offs have an elongated generally cylindrical body member with a threaded shank extending from one end. In the use of such stand-offs, the threaded shank is inserted through a hole in a first printed circuit board and held in place by a nut screwed on to the shank. The body member of the stand-off establishes separation between the first board and another element, such as an adjacent board. However, access to both sides of the first board is necessary to install or remove the stand-offs, should that become necessary.
In another form, prior art stand-offs may include an elongated body member having a shank extending from one end which is adapted to be press-fit into an aperture in a printed circuit board. While such stand-offs can establish a desired separation, and only require access to one side of the board for insertion or removal, the removal of such a device, for example during field-servicing of the instrument, often results in cracking of the board near the aperture, despite attempts to regulate the shear forces required for its removal of the stand-off.
Accordingly, it is an object of the present invention to provide an improved stand-off device which can be easily replaced in the field without destruction of the boards to which it is attached, and without disrupting the positioning of the other components of the instrument.